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Emergency Management of Pneumonia

Dr. Andrew Morris2009.07.13

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ObjectivesMine

to be as brief as possible

to be practical

to be informative

to be provocative

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ObjectivesYours

to appreciate the epidemiology of community-acquired pneumonia

to understand how CAP can be missed ... or diagnosed in lieu of another (correct) diagnosis

to be able to sanely prescribe antibiotics: safely, but rationally also

to get out of lunch rounds early without having to be “paged” out

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Pathogenesis

for almost all pneumonia (save influenza, TB and a few others), the pathogenesis is the same

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Pathogenesis

for almost all pneumonia (save influenza, TB and a few others), the pathogenesis is the same

IDologist.com

Pathogenesis

for almost all pneumonia (save influenza, TB and a few others), the pathogenesis is the same

IDologist.com

Pathogenesis

for almost all pneumonia (save influenza, TB and a few others), the pathogenesis is the same

IDologist.com

CAP epidemiology

approximately 4.5 million cases annually80% of cases are managed as outpatients62 000 deaths/year (adjusted mortality rate of 22/100 000) in US1.4 million hospital discharges in USin Canada, the mortality rate for CAP hovers around 12/100 000

American Lung Association, July 2007www.cdc.gov

www40.statcan.ca

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CAP epidemiology

American Lung Association, July 2007

Change in coding from ICD-9 to ICD-10 in

1999

Pneumonia age-adjusted death rates based on the 1940 and 2000 standard populations, 1979-2003

IDologist.comOutpatient pneumonia is a benign disease

NEJM 1997;336:243-50

“Among the 1575 patients in the three lowest risk classes in the Pneumonia PORT cohort, there were only seven deaths, of which only

four were pneumonia-related.”

only 1 of these 7 patients were managed as an outpatient.

IDologist.comIn-hospital case-fatality is low in

young people

Clinical Infectious Diseases 2003;36:413–421

administrative database from Alberta, looking at all CAP admission from 1994-1999 in adults 18-55

in-hospital case-fatality: 3.2%

10-day case-fatality: 2.1% (most deaths attributed to macroaspiration)

0%

5%

10%

15%

Case-fatality rate

11.9%

4.5%

1.6%

18-39 40-54 ≥55

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pneumonia is usually caused by microaspiration and then replication of pharyngeal bacteriamost pneumonia is a benign disease, especially in young persons

Summary

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most commonly isolated organism, by destination:

outpatient: S. pneumoniæinpatient: S. pneumoniæICU: S. pneumoniæcemetery/crematorium: S. pneumoniæ

however: in patients going to ICU, S. aureus (incl. CA-MRSA) and Legionella (and Gram-negative bacilli) are frequently isolatedMycoplasma, Chlamydophila, H. influenzæ, and viruses are frequently found in outpatients/ward patients

CAP epidemiology

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most likely Dx: Pneumonia (50-60% of the time)other possibilities:

acute bronchitisCHFCOPD/asthma exacerbationpyelonephritispulmonary embolismothers

Pt. in ER referred for “Pneumonia”

Arch Intern Med 2008;168:351-356

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initial assessment:

does this patient need to be isolated before I see him/her?

ABCs

do a relevant history and physical examination

Pt. in ER referred for “Pneumonia”

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is it pneumonia? fever (LR+ 2.1, LR- 0.7)cough (LR+ 1.8, LR- 0.31)chills (LR+ 1.7, LR- 0.85)sweats (LR+ 1.7, LR- 0.83)asthma (LR+ 0.1, LR- 3.8)rhinorrhea (LR+ 0.78, LR- 2.4)

there is no combination of features on history that is suitably reliable for the diagnosis of pneumonia

Relevant history for “Pneumonia”

Ann Emerg Med 2005;46:465-467

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what kind of pneumonia?risk of TB?sick contacts?* travel? animal exposure?*specific forms of immunosuppression

prolonged neutropænia: AspergillusTNF inhibitors: Mycobacteriasteroids, “transplant” meds: PCP, other (esp. dimorphic) fungi

Relevant history for “Pneumonia”

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does patient have pneumonia?Any vital sign abnormality (LR+ 1.2–4.4, LR- 0.5–0.8)Any chest finding (LR+ 1.3, LR- 0.57)Crackles (LR+ 1.6–2.7, LR- 0.9)Egophony (LR+ 8.6, LR- 0.96)Dullness to percussion (LR+ 4.3, LR- 0.93)Decreased breath sounds (LR+ 2.6, LR- 0.64)Asymmetric respirations (LR+ Infinity, LR- 0.95)

Relevant physical exam for “Pneumonia”

Ann Emerg Med. 2005;46:465-467

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does patient need resuscitation?is this severe? home vs ward vs ICU?

PORT score is best validated for overall severity, and so should stick with itCURB-65 widely touted and easy, but not as well validatedSMART-COP appears best for deciding about ICU care

Relevant physical exam for “Pneumonia”

IDologist.comPORT Score

NEJM 1997;336:243-50

http://pda.ahrq.gov/clinic/psi/psicalc.asp

IDologist.comPORT Score

NEJM 1997;336:243-50

IDologist.comCURB-65

2004 BTS Guidelines Update: http://www.brit-thoracic.org.uk/ClinicalInformation/Pneumonia/PneumoniaGuidelines/tabid/136/Default.aspx

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Clinical Infectious Diseases 2008; 47:375–84

SMART-COP

IRVS: Intensive respiratory or vasopressor support

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minimum:CBC; INR/aPTTlytes, urea, creatinine, glucoseliver enzymesSaO2 and/or ABGblood C&S x 2urine R&M +/- C&SCXR

consider:D-dimer and other tests re: PEECGtroponinsputum Gram stain/culturesputum for AFBLegionella urinary antigennp swabs for resp. viruses

Investigations

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although widely recommended (and intuitive), evidence supporting the utility of X-ray is lacking (problem = no gold standard)CXR is not helpful to predict ætiologyat 2 weeks, only 51% of patients had CXR resolution (and only 73% at 6 weeks)clearance of CXR is slower in the elderlyrepeat CXR, though often recommended at 6 weeks, is probably only of value in those who have not fully resolved

Chest X-ray

Am J Respir Crit Care Med 1994;149:630–5

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evidence-based medicine does not support the notion that organisms can be predicted on the basis of history, physical examination and chest x-raythe term “atypical” pneumonia should not be used

Investigations

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patients referred from the ER with pneumonia often have other primary diagnosescough, constitutional symptoms, and abnormal chest findings are helpful to “rule in” pneumonia, but cannot rule it outinvestigations should focus on alternative diagnoses and identifying severity

Summary

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controversialguidelines say one thing, evidence says anotherguidelines vary from country to countryI will give you my take, but feel free to:a) ignoreb)arguec) disparaged)follow

Treatment

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testing is problematic:Legionella urinary antigen is specific, but not tremendously sensitive (< 80%)Mycoplasma IgM is specific, but is usually available post-treatmentChlamydia testing is unreliable

Atypical pathogensTesting

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there are 3 meta-analyses that have looked at treatment of CAP

1 meta-analysis involving 18 trials and 6749 participants: no difference when covering for atypicals1 meta-analysis focused on outpatients involving 13 trials and 4314 patients: no difference when covering for atypicals1 meta-analysis focused on inpatients involving 24 trials and 5015 patients: no difference when covering for atypicals

Atypical pathogensTreatment

BMJ, doi:10.1136/bmj.38334.591586.82Eur Respir J 2008;31:1068-76

Arch Intern Med 2005;165:1992-2000

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which of the following agents have been associated with bacteriologic failure (i.e. clinical failure due to failure to treat the S. pneumoniæ) in pneumococcal pneumonia?a) azithromycinb) ceftriaxonec) cefuroximed) levofloxacine) penicillinanswer: a), c), d)

CAPTreatment Quiz

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there is not a single randomized, blinded trial that has ever shown one agent or a combination of agents to be superior to penicillin for CAPbecause S. pneumoniæ is the most likely pathogen, covering it receives the highest priorityoptions for treating S. pneumoniæ

penicillin or ampicillin (i.v.)/amoxicillin (p.o.)cefotaxime or ceftriaxonedoxycyclinerespiratory FQ (levofloxacin or moxifloxacin)

CAPTreatment

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for patients heading to the ICU, the approach should differ, because you need to cover for S. aureus (sometimes including MRSA) and Legionella in addition to S. pneumoniæoptions (and there are many more, none based on RCTs): ceftriaxone + (respiratory FQ or macrolide) +/- vancomycin +/- oseltamivir

ORvancomycin + (respiratory FQ or macrolide) +/- oseltamivirceftriaxone + TMP/SMX (for CA-MRSA and Legionella) +/- oseltamivir

CAPTreatment - ICU

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there are no RCTs demonstrating a mortality benefit of antiviral therapy for CAPstudies of influenza in otherwise healthy adults with influenza showed that neuraminidase inhibitors shorten duration of illness by about 1 day

CAPTreatment-Antivirals

N Engl J Med 2005;353:1363-73

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meta-analysis of trials prior to 2002 involving influenza+ high-risk patients >65 yrs or with chronic medical conditions reported zanamivir ⬇time to

alleviation of symptoms by 2d and that oseltamivir did so by about ½ daya Canadian study in long-term care facilities showed that elderly patients given oseltamivir within 48 hours after onset of symptoms were considerably less likely to be prescribed antibiotics, to be hospitalized, or to die

CAPTreatment-Antivirals

BMJ 2003;326:1235

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prospective study from January 2005-May 2006 of patients hospitalized with influenza in southern Ontario327 adults (median age 77; 75% with chronic underlying illness)

89% received antibacterials; 32% prescribed antivirals36% of those no receiving antivirals were admitted to ICU, compared with 16%22% vs 4% 15-day mortality

CAPTreatment-Antivirals

Clin Infect Dis 2007;45:1568-75

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treatment of patients for CAP should include an agent expected to be effective for S. pneumoniæif patients are heading to the ICU, then cover for Legionella and CA-MRSAif there is plenty of influenza going around, add oseltamivir

Summary

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there is little evidence to support followup investigations in patients who are clinically improving

leukocytosis and CXR do not correlate well with clinical improvement: treat the patient, not the labsgive at least 72h to respond

if hæmodynamically stable, eating and improving, can probably step-down to oral therapyas a minimum, a chest x-ray should be performed at 6 weeks (to ensure resolution) if patient not clinically back to baseline health

CAPAfter Day 1

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patient not responding

resistance/inadequate therapyempyema/effusionalternate diagnosis

patient worseningnatural history of diseaseresistance/inadequate therapysecondary infectionalternate diagnosis

CAPAfter Day 1: Misbehavin’

IDologist.comCAPAfter Day 1: Misbehavin’

Effect of Therapy on Percent Survival in Pneumococcal Bacteremia

0

10

20

30

40

50

60

70

80

90

100

0 5 10 15 20

Day of Illness

% S

urv

ivors

Symptomatic

Serum

Penicillin

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QUESTIONS?